1. Field of the Invention
The invention relates to a printer. In particular, the invention relates to an actuator in a recording device, and connecting the actuator to a driving circuit via a flexible printed circuit.
2. Description of Prior Art
Conventionally, in a printer for recording an image on a recording medium, a printed circuit board that drives a recording head (an actuator) is disposed far from a nozzle of the printer. This avoids staining the printed circuit board with superfluous ink, such as ink mist that is generated when ink is jetted from the ink jetting nozzle during recording. The recording head and the driving printed circuit board are electrically connected via a flexible printed circuit.
FIG. 8 shows an example of a head unit of the printer. FIG. 8 is an exploded perspective view showing the head unit. A head unit 100 is provided with a recording head 2 that records according to an ink-jet method, a head holder 3 on which the recording head 2 is fixed, a head guide 4 that protects the recording head 2, a case holder 6 that protects an ink cartridge 5, in which ink is filled, and a printed circuit board 7 that drives the recording head 2, and a manifold 8 that supplies ink from the ink cartridge 5 to the recording head 2. Seal rubber 10 is attached to an end of the manifold 8. A flexible printed circuit 21, provided with electrodes in pitch corresponding to the nozzles of the recording head 2, is connected to the recording head 2. The recording head 2 and the printed circuit board 7 are electrically connected by connecting the flexible printed circuit 21 to the recording head 2 and to a connector 7B of the printed circuit board 7, which is disposed at an opposite side of the head holder 3 from the recording head 2.
Further, as shown in FIG. 9 in detail, the flexible printed circuit 21 is formed so that one end is provided with a characteristic electrode pitch which corresponds to the nozzles of the recording head 2, and the other end is provided with an electrode pitch which is suitable for connecting to the connector 7B of the printed circuit board 7.
However, this conventional structure is subject to the problem that, since the flexible printed circuit 21 must be manufactured so that the one end is provided with the characteristic electrode pitch corresponding to the nozzles of the recording head 2, the manufacturing cost of the flexible printed circuit 21 is comparatively high, and thus the manufacturing cost of the printer is comparatively high. The flexible printed circuit 21 is long because it is connected to the printed circuit board 7, which is disposed far from the nozzles of the recording head 2. The handling of the flexible printed during its manufacture, and the handling of the recording head 2 after the flexible printed circuit is attached, are difficult. It is also difficult to automate the manufacture. Therefore, the manufacturing cost is comparatively high.
It has been proposed to reduce the manufacturing cost of a printer by electrically connecting a recording head and its driving circuit via a flexible printed circuit that is provided with electrodes in pitch corresponding to the nozzles of the recording head, and a general purpose flexible printed circuit.
However, since electrodes of the flexible printed circuit that are in pitch corresponding to the nozzles of the recording head and the general purpose flexible printed circuit may be exposed, the problem arises that superfluous ink that is generated when the printer is operated, as well as various cleaning solvents and other materials used during manufacturing, adhere to the exposed electrodes. The connection is dirtied by the ink and other materials, and the connection fails.